Superplastic Bulging of Nanocrystalline Ni-Co Alloy with Different Heating Methods

2012 ◽  
Vol 735 ◽  
pp. 136-139
Author(s):  
Guo Feng Wang ◽  
Shao Song Jiang ◽  
Zhen Lu ◽  
Kai Feng Zhang
Keyword(s):  
Nanocrystalline Materials ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Hot Spot ◽  
Tensile Tests ◽  
Complex Stress ◽  
Resistance Heating ◽  
Furnace Temperature ◽  
Temperature Heating ◽  
Room Temperature Strength

Superplasticity of nanocrystalline materials is a hot spot in the field of scientific research. In this paper, Ni-Co alloy was produced through pulse electrodeposition. Tensile tests were carried out to study the room temperature strength, high temperature plasticity. The superplastic formability under complex stress was evaluated through the superplastic bulging tests. The tests were studied through the methods of resistance heating and furnace temperature heating. The maximum ratios of height and diameter with different heating method were compared. Fracture behavior and microstructure were observed by the method of SEM.

Ductility and Fracture Behavior of Single Crystalline Ni3Al with Boron Additions

1988 ◽  
Vol 133 ◽  
Author(s):  
F. E. Heredia ◽  
D. P. Pope
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strengthening Effect ◽  
Single Crystalline ◽  
B Additions ◽  
High Temperature Tensile ◽  
Tension Compression Asymmetry ◽  
Positive Effect

ABSTRACTLow and high temperature tensile tests were performed on single crystals of pure Ni3Al and Ni3Al+B in order to determine the effect of B additions on the ductility and fracture behavior. Tests were carried out in air at a constant strain rate of 1.3 × 10−3 s−1. The orientations tested were [001] for which the yield stress in tension is always greater than in compression, and those for which the tension/compression asymmetry is zero ([T=C]) for each particular composition. At room temperature, the results show a positive effect of B additions on both the fracture stress and on the ductility. The ductility at 800K appears to decrease monotonically with B additions. The largest ductilities are found for [T=C] at room temperature where an improvement of about 26% (resolved strain) for an addition of 0.2 at% B was obtained. However, the most dramatic increase in ductility occurs for the [001] oriented samples at room temperature where a 55% improvement was measured over that of pure Ni3Al. Fracture surfaces show a combination of massive slip, some cleavage, and heavily dimpled areas. These observations show that B additions not only increase the ductility of polycrystalline Ni3Al, as has been previously observed by many investigators, but also that of the already-ductile single crystalline material, indicating that a “bulk effect” should be added to the grain boundary strengthening effect of B when explaining the improvement in ductility of polycrystalline Ni3Al due to B additions.

Effect of RE Content on the Fracture Behavior in Mg-Gd-Nd-Zr Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 199-202 ◽  
Author(s):  
Kai Yun Zheng ◽  
Jie Dong ◽  
Xiao Qin Zeng ◽  
Wen Jiang Ding
Keyword(s):  
Cleavage Fracture ◽  
Fracture Mechanism ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Tensile Tests ◽  
Relative Strength ◽  
Sem Images ◽  
Fracture Surfaces ◽  
Treated Condition ◽  
Zr Alloys

Tensile tests were performed on T4-treated specimens of GN62K (Mg-6Gd-2Nd-Zr(wt%)) and GN112K (Mg-11Gd-2Nd-Zr) alloys at room temperature and on T6-treated ones from room temperature to 300°C. The fracture behavior was investigated by using SEM images of fracture surfaces together with optical metallographs adjacent to the surface. Quasi-cleavage fracture was observed in the fracture surfaces of both alloys in T4-treated condition, and it seems that RE content has no significant effect on the fracture mechanism in T4-treated alloys. As for T6 treated condition, cracking was in a manner of transgranular cleavage and/or quasi-cleavage fracture in GN62K alloy but intergranular fracture in GN112K alloy, which implies that the fracture mechanism in T6-treated Mg-Gd-Nd-Zr alloys can be altered by the amount of RE addition. This phenomenon is interpreted in association with the relative strength of grain bulk and boundary.

Research on Effect of Alloy Elements on Equilibrium and Properties of Ni-Cr-Co Type Nickel-Based Superalloy

2016 ◽  
Vol 849 ◽  
pp. 513-519
Author(s):  
Qing Quan Zhang ◽  
Ming Yang Li ◽  
Ran Wei ◽  
Hui Yun Wu ◽  
Zhen Rui Li
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
High Temperature Strength ◽  
Nickel Based Superalloy ◽  
Type 3 ◽  
Room Temperature Strength ◽  
Super Alloy ◽  
Type Nickel

Ni-Cr-Co type Nickel-based super alloy Inconel 740H was studied. The effect of Nb, Al and Ti on the equilibrium of this alloy was analyzed by JMatPro software. The amount of Ti and Nb should be controlled by 1.50wt.%, and meanwhile, Al should be 1.0-2.0wt.%. If Mo and W were added the amount of Mo should be in the range of 1.0-2.0wt. %, and W should be about 1.0wt.%. Based on these results, three types of new alloys were designed, which contain Ni-Cr-Co-Mo type (1#), Ni-Cr-Co-W type (2#) and Ni-Cr-Co-Mo-W type (3#). Compared with the Ni-Cr-Co type Inconel 740H alloy, the room temperature strength, high temperature strength and high temperature durable performance of the three new alloys improved, which can provide the evidence and reference to optimize the chemical composition of Inconel 740H alloy, i.e., adding 1.50wt.% Mo and 1.0wt.% W individually or together.

Deformation Twins Formed in Nanocrystalline Materials

2006 ◽  
Vol 503-504 ◽  
pp. 125-132 ◽  
Author(s):  
Yuntian T. Zhu
Keyword(s):  
Grain Boundaries ◽  
Nanocrystalline Materials ◽  
Partial Dislocation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Nucleation And Growth ◽  
Analytical Models ◽  
Partial Dislocations ◽  
Deformation Twins ◽  
Low Strain Rate

Deformation twins have been oberved in nanocrystalline (NC) Al synthsized by cryogenic ball-milling and in NC Cu processed by high-pressure torsion under room temperature and at a very low strain rate. They were found formed by partial dislocations emitted from grain boundaries. This paper first reviews experimental evidences on deformation twinning and partial dislocation emissions from grain boundaries, and then discusses recent analytical models on the nucleation and growth of deformation twins. These models are compared with experimental results to establish their validity and limitations.

Influence of Heat Treatment on Microstructure and Mechanical Properties of Selective Laser Melted TiAl6V4 Alloy

2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Room Temperature ◽  
Base Alloy ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Treatment Procedures

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.

Effect of Rolling Parameters on the Properties of Al-Fe-V Sheet Rolled on an Experimental Mill

1985 ◽  
Vol 58 ◽  
Author(s):  
A. Brown ◽  
D. Raybould
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Aluminum Alloys ◽  
Room Temperature ◽  
Thermomechanical Processing ◽  
High Temperature Strength ◽  
Rapidly Solidified ◽  
Large Sheet ◽  
Room Temperature Strength

ABSTRACTIn recent years, interest in high temperature aluminum alloys has increased. However, nearly all the data available is for simple extrusions. This paper looks at the properties of sheet made from a rapidly solidified Al-10Fe-2.5V-2Si alloy. The sheet is made by direct forging followed by hot rolling, this is readily scalable, so allowing the production of large sheet. The room temperature strength and fracture toughness of the sheet are comparable to those of 2014-T6. The high temperature strength, specific stiffness and corrosion resistance are excellent. Recently, improved thermomechanical processing and new alloys have allowed higher strengths and fracture toughness values to be obtained.

Embedded resistive heating in composite scarf repairs

2016 ◽  
Vol 51 (18) ◽  
pp. 2575-2583 ◽  
Author(s):  
Mahdi Ashrafi ◽  
Brandon P Smith ◽  
Santosh Devasia ◽  
Mark E Tuttle
Keyword(s):  
Temperature Distribution ◽  
Outer Surface ◽  
Thermal Gradient ◽  
Thermal Damage ◽  
Electrical Current ◽  
Tensile Tests ◽  
Resistance Heating ◽  
Uniform Temperature ◽  
Uniform Temperature Distribution ◽  
Bond Strengths

Composite scarf repairs were cured using heat generated by passing an electrical current through a woven graphite-epoxy prepreg embedded in the bondline. Resistance heating using the embedded prepreg resulted in a more uniform temperature distribution in the bondline while preventing any potential thermal damage to the surface of the scarf repairs. In contrast, conventional surface heating methods such as heat blankets or heat lamps lead to large through thickness thermal gradient that causes non-uniform temperature in the bondline and overheating the outer surface adjacent to the heater. Composite scarf repair specimens were created using the proposed embedded heating approach and through the use of a heat blanket for circular and rectangular scarf configurations. Tensile tests were performed for rectangular scarf specimens, and it was shown that the bond strengths of all specimens were found to be comparable. The proposed embedded curing technique results in bond strengths that equal or exceed those achieved with external heating and avoids overheating the surface of the scarf repairs.

Spark Plasma Sintering of Ti-4.5Al-3V-2Fe-2Mo (SP-700)

2010 ◽  
Vol 654-656 ◽  
pp. 819-822
Author(s):  
Genki Kikuchi ◽  
Hiroshi Izui ◽  
Yuya Takahashi ◽  
Shota Fujino
Keyword(s):  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Volume Fraction ◽  
Titanium Boride ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Tib2 Particles

In this study, we focused on the sintering performance of Ti-4.5Al-3V-2Mo-2Fe (SP-700) and mechanical properties of SP-700 reinforced with titanium boride (TiB/SP-700) fabricated by spark plasma sintering (SPS). TiB whiskers formed in titanium by a solid-state reaction of titanium and TiB2 particles were analyzed with scanning electron microscopy and X-ray diffraction. The TiB/SP-700 was sintered at temperatures of 1073, 1173, and 1273 K and a pressure of 70 MPa for 10, 30, and 50 min. The volume fraction of TiB ranged from 1.7 vol.% to 19.9 vol.%. Tensile tests of TiB/SP-700 were conducted at room temperature, and the effect of TiB volume fraction on the tensile properties was investigated.

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